Traveling plow feeder



D. SVOBODA TRAVELING PLOW FEEDER April 29, 1969 Sheet of 3 Filed Sept. '7, 1967 INVENTOR.

DANIEL SVOBODA April 29, 1969 SVOBQDA 3,441,149

TRAVELING PLOW FEEDER Filed Sept. 7, 1967 Sheet 2/ of 3 INVENTOR.

F l G. 3. DAN I EL. SVO BO DA April 29, 1969 D. SVOBODA TRAVELING PLOW FEEDER Sheet Filed Sept.

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United States Patent 3,441,149 TRAVELING PLOW FEEDER Daniel Svoboda, Denver, Colo., assignor to The Stearns- Roger Corporation, Denver, Colo., a corporation of Colorado Filed Sept. 7, 1967, Ser. No. 666,133 Int. Cl. B65g 47/16, 65/30; A01f 25/00 US. Cl. 214-17 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a carriage mounted retractable plow used for selective reclaim of free-flowing granular materials resting atop shelves located in a tunnel beneath piles of said materials. More specifically, the unit comprises a remotely-controlled carriage that runs back and forth within a tunnel which has shelves onto which the material being reclaimed flows through openings in the tunnel wall. The carriage has mounted thereon at least two plows, each of which is remotely actuatable into an operative position where it will sweep the material from the shelf into a hopper carried by the carriage for deposit upon a belt conveyor running therebeneath. One 'set of the plows is retracted at all times while the other set is either extended into its operative sweeping position or, if desired, retracted to bypass certain of the material. Then, upon reverse movement of the carriage, the formerly deactivated set of plows is energized so that they can be extended into operative position while the other set is folded into inoperative position.

Traveling plow mechanisms for the reclaim of freeflowing granular materials from beneath a pile thereof are in common use. In general, these reclaim systems comprise a tunnel buried beneath several piles of the material to be reclaimed. These piles are replenished from time-totime as the supply thereof dwindles. The tunnel has openings along the sidewalls thereof through which the freeflowing granular materials gravitate onto interior shelves. Between and beneath these shelves runs an endless belt conveyor that carries the material taken from the shelves out through one end of the tunnel. The height of the openings in the tunnel sidewalls is selected in relation to the width of the shelves and the inherent angle of repose of the particular material such that virtually all of the material flowing into the tunnel will be retained atop the shelf and not reach the conveyor until positive measures are taken to remove it therefrom. Actual removal of the material from the shelves onto the conveyor is accomplished in the prior art systems by some type of plow arrangement that moves through the tunnel and sweeps the material from the shelves.

While systems of the above type have proven quite satisfactory for many bulk storage reclaim systems, certain limitations are inherent therein which render them completely unsuitable in instances where a degree of selectivity in the reclaimed product is desired. For instance, it is not at all uncommon to find bulk storage warehousing facilities where it would be desirable to store more than one type or different grades of the same type of material provided that it were possible to bring about a selective reclaim thereof. In so doing, material of one type or grade could be taken from the tunnel without disturbing the others and it would even be possible to accomplish some selective blending. Even in those instances where all of the material was of the same type and grade, instances might well arise where selecting material from a particular location would be of advantage due to its age, abundance or some other property.

Regardless of the reason for needing the ability to 3,441,149 Patented Apr. 29, 1969 select material from certain sections of the bulk storage facility in preference to others, the fact remains that the present tunnel reclaim systems make no provision therefor.

In accordance with the teaching of the instant invention, on the other hand, the carriage-mounted retractable plows enable the operator to pick and choose from what portion of the stockpile he will take the material and thus give him more or less complete control over the type, grade and even the quantity of material withdrawn therefrom. As the unit moves along its track in one direction, one set of the plows is rendered operative; whereas, when moving in the opposite direction, a second set is activated while the first set is folded and made inoperative. Each so-called set of foldable plow members can have one or more plow units therein depending upon the desired capacity. The rate of removal of the material is also dependent, of course, upon the conveyor capacity and the speed of the carriage. The faster the carriage traverses the tunnel, the greater the spacing generally required between plow units of a given set in order to enable additional material to flow in behind the lead plow unit so as to be picked up by the second. Obviously, each plow unit sweeps the shelf essentially clean as it moves therealong and, unless more material is deposited on the shelf after the lead plow passes by, there is no need for additional units in a particular set.

Remotely-actuated electrically-operated piston servomotors are used to extend and retract all plow units of a given set simultaneously. In folded position, the plows ride between the shelves so as to leave the material deposited thereon undisturbed. Limit switches carried by the carriage function upon actuation to reverse the direction of movement of the carriage and also to render one set of plows operative while deactivating the other set. Winches at opposite ends of the tunnel alternately operate to pull the rail-mounted carriage from end-to-end.

Itis, therefore, the principal object of the present invention to provide a novel and improved traveling plow feeder with retractable plows.

A second objective of the invention herein disclosed and claimed is to provide a mechanism for accomplishing the selective removal of free-flowing granular materials from beneath one or more piles thereof.

Another object is to provide plow-type feeding apparatus that includes two sets of plows, one operative in each direction of carriage travel to sweep a tunnel shelf essentially clean of material deposited thereupon.

Still another objective of the invention forming the subject matter hereof is the provision of a foldable plow subassem-bly that can be retracted at the will of the operator so as to bypass certain unwanted portions of a pile of granular material while gathering others.

An additional object is to provide a multiple plow unit of the type aforementioned which, with proper plow spacing, results in a greatly increased capacity.

A further object of the invention is to provide a bulk storage reclaim system that is efficient, versatile, dependable, easy to operate, rugged and readily adaptable for use in various warehousing facilities on the same or different grades and types of free-flowing granular materials.

Other objects will be in part apparent and in part pointed out specifically hereinafter in connection with the description of the drawings that follows, and in which:

FIGURE 1 is a top plan view of the rail-mounted carriage and retractable plow subassembly carried thereby;

FIGURE 2 is a side elevation of the unit showing same mounted atop the rails, the latter having been broken away to conserve space;

FIGURE 3 is a vertical section to an enlarged scale taken along line 3-3 of FIGURE 2 showing, in addition, the tunnel housing the reclaim apparatus;

FIGURE 4 is a fragmentary detail to an enlarged scale showing the specific elements of the link assembly used to extend and retract each set of plows;

FIGURE 5 is a schematic electrical diagram showing the electrical controls for the carriage drive incorporating bot-h automatic and manual operation;

FIGURE 6 is a schematic view illustrating an electrical circuit for energizing and de-energizing the servo-motors that operate the plow sets;

FIGURE 7 is a schematic view of a carriage-mounted control circuit responsive to carriage movement and operative to automatically switch one or the other sets of plows into operative condition depending upon the direction of carriage movement; and,

FIGURE 8 is a remotely-located control circuit similar in function to that of FIGURE 7 except that a manual override of the operative set of plows is provided for so as to give the operator a choice concerning the portion of the pile material to be reclaimed.

Referring now to the drawings for a detailed description of the present invention and, initially, to FIGURES 1-3 for this purpose, reference numeral 10 has been employed to broadly designate a wheeled carriage mounted for rolling movement upon rails 12 that run inside a tunnel structure 14. This tunnel structure is largely conventional and includes more or less vertically disposed sidewalls 16 separated from an arched roof portion 18 by horizontal window-like openings 20 that generally extend the full length of the tunnel except for the inclusion of occasional structural members 22 that bridge the gap between the walls and the roof. In the particular form illustrated, the height of these windows 20 is selected in relation to the width of shelves 24 disposed inside the tunnel along the bottom edge of said windows such that the angle of repose of the free-flowing granular material (not shown) that enters the tunnel therethrough will all be contained within the confines of the shelves until swept therefrom. If the tunnel is to be used beneath piles of materials having substantially different angles of repose, it is a simple matter to equip the window openings with overhead vertically adjustable gates (not shown) which can be lowered as necessary to accommodate materials having a shallow angle of repose.

Ordinarily, the bulk granular material will be dumped in through overhead openings in the roof of the storage warehouse so as to cover the tunnel completely, the apex of the pile being more or less centered atop the tunnel. The instant bulk storage reclaim system is particularly well-suited to those bulk storage reclaim applications wherein selective removal of two or more different types or grades of material is to be accomplished without appreciable intermixing thereof. If this is the case it is, of course, necessary to keep the piles separated from one another outside the tunnel either by leaving a space therebetween or interposing some type of vertical barrier (not shown). In any event, the material piled atop the tunnel will enter same through the windows 20 by gravity alone and deposit itself upon the shelves 24 running 'along the walls thereof in the well-known manner.

Now, mounted upon the floor of the tunnel are a pair of longitudinally-extending spaced parallel rail supports 26 interconnected at intervals by cross braces 28. Fastened atop these supports which, in the particular form shown, have a hollow rectangular cross section, are I- beams 30 that carry the rails 12 atop the upper flanges thereof. Interposed between the rails 12 in centered relation therebetween is a troughed 'belt conveyor assembly 32 of conventional design, the belt-supporting rollers 34 of which would be mounted on the same frame elements (26 and 28) that carry the rails although no specific structural interconnection therebetween has been illustrated as it forms no part of the instant invention.

The carriage or trolley 10 assumes the general form of a hopper car except that the hoppers 36 are always open through chutes 38 to the conveyor belt 32 located immediately therebeneath. In other words, any material swept off the tunnel shelves by the retractable plow subassembly which has been indicated in a general Way by reference numeral 40, is deposited in the hoppers 36 and immediately delivered thereby onto the conveyor 32 through chutes 38 from one end of the tunnel.

In the particular form illustrated, the carriage includes a frame having horizontal sideframe elements 42 that journal the axles 44 upon which the grooved wheels 46 are mounted. Intermittent cross bracing 48 ties the side-frame elements 42 together while leaving the bottom more or less open to receive the hopper chutes 38. Triangular plates 50 together with uprights 52 rest atop the cross frame members 48 and cooperate with one another to support the upwardly and outwardly divergent sides 54 of the hoppers. A pair of longitudinally-extending spaced parallel channels 56 interconnected at intervals by cross braces 58 extend alongside and between the tops of the hopper to provide the structural support for centerposts 60 of the plow subassembly. The adjacent free edges of the shelves 24 terminate in spaced relation so as to leave a passageway 62 therebetween for the movement of posts 60. 7

As shown most clearly in FIGURES 1 and 2, four separate hoppers are provided within the carriage, one for each set of plows, there being four sets of the latter in all, two sets of which are operative as the carriage moves forward and the remaining two when it moves in reverse. The posts 60 that carry each of the plow sets are preferably located at the rear extremity of their particular hopper so that they push the material from the shelves ahead thereof and into the awaiting hopper. Obviously, the term rear as used above in relation to the hoppers refers only to the particular pair of sets that is operative at any given time and then with reference to the direction of carriage movement within the tunnel.

Next, with reference to FIGURES 1-4, inclusive, the details of the retractable plow subassemblies 40 will be set forth in detail. The vanes 64 of the plows are attached by hinges 66 to opposite sides of the posts 60 for horizontal pivotal movement from a retracted parallel relation to one another lying wholly within the confines of passage 62 and their extended operative position wherein they form a V with one another and essentially scrape the top surfaces of the tunnel shelves 24 clean of material. The outer ends 68 of the vanes are cut on the bias so that the lower margins thereof can pass as close as possible to the arched tunnel roof. In the particular form shown, the vanes when extended bear approximately 90 to one another and 45 on opposite sides of the direction of carriage travel although, of course, difierent angular relationships may be used and still accomplish the necessary sweeping action from the shelves into the hoppers of the carriage.

Vanes 64 are hingedly attached to their respective posts at points spaced inwardly of their adjacent ends as shown most clearly in FIGURE 4 to which specific reference will now be made. Ears 70 upstanding from the adjacent extremities of each pair of plow vanes receive pivot pins 72 that pivotally attach same to connecting links 74. The other ends of these connecting links are likewise pivotally attached to connector plate 76 by pivot pins 78. Plate 76 is, in turn, fixedly attached to the adjacent ends of a pair of connecting rods 80 that are guided for horizontal reciprocating movement along the longitudinal centerline of the carriage by guide members 82 mounted atop plates 84 that are fastened to the posts 60. Thus, movement of the connecting rod to the right as viewed in FIGURE 4 will move the vanes 64 from their extended full-line position into their retracted dotted-line position. Conversely, a pull exerted on the connecting rod will extend the vanes into operative position. Connecting rods 80, therefore, are responsible for actuating the remote set of plow vanes in each pair of sets thereof, the term emote as used herein meaning that set farthest from the servo-motor 86 that actuates both sets simultaneously as will be explained presently.

Again referring to FIGURES l and 2, it will be noted that a second plate 84 rests atop the post 60 that carries the set of plows adjacent the servo-motor 86 which serves as a support for the latter. Said servo-motor includes a reciprocating thruster rod 90 that operatively connects to the adjacent set of plows 64 by the same general type of triangular plate 76, links 74, ears 70 and pivot pins 72 and 78 as was the case with the remote set of plows and connecting rod 80. Thus, reciprocating motion of thruster rod 90 of the servo-motor extends and retracts the adjacent set of plows and it also acts through thruster rod 90 attached at both extremities to the plates 76, to operate the remote set of plows. Accordingly, the two sets of plows connected to each of the servo-motors operate simultaneously upon actuation of their respective servomotors. At no time are both servo-motors actuated at the same time to extend the plows although, as will be ex plained presently, all four sets may be retracted at the same time when the unit is being operated to accomplish selective reclaim.

Before proceeding further, a discussion of the servomotors 86 should, perhaps, be undertaken. The sole function to be performed by these servo-motors is that of extending and retracting the one or more sets of plows operatively connected thereto either automatically or in response to a signal from an operator at a remote station outside the tunnel. It is, of course, obvious that many different types and styles of servo-motors are well-known in the art capable of accomplishing this simple mechanical function. For example, a small hydraulic piston servomotor operated by an electric pump equipped with the necessary remotely-actuated solenoid valves to change the direction of fluid flow would be a simple matter for an engineer to install and such a system would have the desirable characteristics of a positive plow drive in both directions along with suflicient power and reliability to withstand considerable abuse. A pneumatic system patterned along the same lines as the hydraulic system above-described could also be used. The electro-mechanical system illustrated herein is, therefore, intended as being merely representative of the general type of plow-actuating apparatus that could be installed by anyone of ordinary skill and the system is by no means limited to use of the particular mechanism shown, the latter having been selected primarily because of its simplicity.

Accordingly, as shown, the servo-motors 86 are of the conventional type wherein the thruster rod 90 is extended to retract the plows in response to the mechanical action of a compression spring behind said rod; whereas, retraction of the piston rod to extend the plows is accomplished electrically by impressing a current upon a coil contained therein of suflicient magnitude to overcome the bias exerted upon the rod by the spring. With such a system, the plows retract automatically whenever the servo-motors are deactivated and it is only when current is supplied thereto that the plows extend into their operative positions.

The carriage is shown in FIGURES 1 and 2 equipped with four sets of plows in all, two that are operative when traveling in one direction and the remaining two when the carriage moves in the opposite direction. The unit can, of course, be equipped with single instead of double sets of plows or, for that matter, triple or quadruple sets thereof depending upon the needs of a particular bulk storage reclaim operation. As aforementioned, whenever more than single sets of plows are used, the rate of carriage movement must be such as to permit additional material to flow in behind the lead plow to be picked up by the second-in-line, third, etc.; otherwise, there will be no material present for them to take off the shelves.

Once again referring to FIGURES l, 2 and 3, it will be seen that the carriage is hauled back and forth through the tunnel by cables 92 attached to opposite ends thereof.

For purposes of the present description, it is intended that a single reversible winch mechanism 94 (represented schematically in FIGURE 5) be located at one end of the tunnel. The hauling cable 92 would, in such a system, pass from one end of the carriage down to the far end of the tunnel, over an idler sheave, back along the bottom of the tunnel to the winch at the lead end, and thence to the other end of the carriage, none of the latter mechanism having been specifically illustrated as it is entirely conventional in many haulage systems. Here again, the winch and haulage cable system could easily be replaced by a self-contained reversible electric motor drive mounted directly on the carriage that was responsive automatically to reverse directions upon contacting limit switches at opposite ends of the tunnel. Accordingly, the carriage drive is also intended as being merely illustrative of one such drive that could be employed to move the carriage back and forth in the tunnel and it is, by no means, the only such drive that could be used.

Referring briefly to FIGURE 3, electrical power to operate the servo-motors, control switches and the like is delivered thereto by electrical leads 96 that run the entire length of the tunnel underneath protective cover-plate 98 mounted alongside one of the supports 26. Projecting from one side of the carriage is an outrigger subassembly 100 which forms a trolley that carries brush or roller-type electrical pick-ups 102 that receive current from leads 96 and carry it to the carriage through suitable conductors.

Referring now to FIGURE 5, the circuit to accomplish both manual and automatic operation of the winch will be set forth. Mode control switch 104 is shown switched to the manual mode wherein movement of the carriage is controlled by FORWARD switch 106 and REVERSE switch 108. Connected in series with FORWARD switch 106 are the normally-closed contacts 110 of a forward limit switch, the normally-closed contacts 112 of an emergency forward limit switch, the normally-closed reverse contacts 114 of winch reverse starter coil 94R, and the forward winch starter coil 94F. When the FORWARD switch 106 is closed, the carriage begins to move forward through the tunnel and energization of forward winch starter coil 94F actuates the normally-closed contacts 116 thereof to open position thus immediately rendering the parallel carriage reverse circuit inoperative even though REVERSE switch 108 were closed. As long as switch 106 is held closed, the carriage will continue to move forward until the forward switch actuator (not shown) contacts forward limit switch contacts 110 and opens them to de-energize the circuit. The latter switch actuator is placed at the far end of the tunnel in position to first contact forward limit switch contacts 110 or, failing to operate the latter, then the emergency forward limit switch contacts 112, both of which are shown in FIGURE 2. A normally-closed overload switch 120 is also shown connected in series with both the forward and reverse circuits for obvious reasons. Once either switch contact 110 or contact 112 open, starter coil 94F is de-energized allowing contacts 116 thereof to reclose, thus rendering the reverse control circuit operative once again upon closure of switch 108. Reverse limit switch contacts 122 of a reverse limit switch and emergency reverse limit switch contacts 124 of an emergency reverse limit switch are both normally-closed and connected in series with the normallyclosed contacts 116 of forward winch starter coil 94F as well as reverse winch starter coil 94R and overload switch 120. As soon as switch 108 is closed, reverse winch starter coil 94R energizes to open contacts 114 so as to render the forward carriage control circuit inoperative even though switch 106 were to be closed. In all respects, the carriage reverse control circuit operates in the same way as just described with reference to the forward carriage control circuit.

Now, when the mode selector switch 104 is shifted to the other contact, it places the circuit in the AUTO- MATIC rather than the manual mode. Instantaneous closure of normally-open START switch 126 energizes relay 128 to close the normally-open contacts 130 thereof and hold the circuit closed through normally-closed STOP switch 132 even though START switch 126 is released to its normally-open position. Energizing relay 128 also closes a second set of normally-open contacts 134 which operates through whichever set of time delay relay contacts 136E or 136R happens to be closed at the time. As illustrated, time delay relay contacts 136E are closed to energize normally-closed contacts 110, 112, 114, 120 and the forward winch starter winding 94F connected in series therewith, the operation of which has already been described in detail. The other set of time delay relay contacts 136R are similarly connected in series with normallyclosed contacts 122, 124, 116, 120 and the winch reverse starter winding 94R that controls reverse movement of the carriage.

As the carriage moves forward to the far end of the tunnel in AUTOMATIC mode, it contacts the switch actuator which trips the forward limit switch opening contacts 110 thereof while simultaneously closing a second set of normally-open forward limit switch contacts 138. As the latter contacts close, coil 140 is energized thereby closing its normally-open contacts 142 that energizes the time delay relay 144 which controls time delay relay contacts 136R and 136F previously mentioned. Thus, once the time delay relay 144 has been energized, its closed contacts 136F open after a brief time interval and its open contacts 136R close to ready the carriage control circuit for reverse movement. It should be mentioned that the emergency forward limit switch also has a second set of normally-open contacts 146 connected in parallel with contacts 138 to energize coil 140 and trip time delay relay 144 in case of a failure in the primary forward limit switch. Now, after a suitable time interval determined by relay 144, contacts 136R thereof close completing the reversing circuit through the reverse limit switch contacts 122, normally-closed contacts 124, 116 and 120, and reverse starter winding 94R which starts the carriage backing up. Then, as the carriage reaches the front end of the tunnel and the switch actuator (not shown) trips either contacts 122 or 124- into open position (FIGURE 2), a second set of normally-open contacts (148 of the reverse limit switch or 150 of the emergency reverse limit switch) are closed to, once again, energize coil 140 and close its normally-open contacts 142 so as to trip relay 144. This relay, again, reverses contacts 136R and 136F, opening the former and closing the latter to complete the cycle and ready the carriage for forward movement. This cycle continues over and over automatically until normally-closed STOP r switch 132 is opened to de-energize coil 128 allowing contacts 130 thereof to open and break the control circuit.

Finally, reference will be made to FIGURES 6, 7 and 8 for a detailed description of the plow-operating servomotors. First, with regard to FIGURE 7, the carriage is equipped with a pair of so-called rotation switches 152 and 154 attached to a wheel. One of these rotation switches 152 responds to rotation of the carriage wheel only in the direction to move the carriage forward and thus is closed by such motion while remaining open at all other times. The other rotation switch 154 closes in response to reverse movement of the carriage and remains open at all other times. As shown in FIGURE 7, rotation switch 154 is closed meaning the carriage is moving in reverse or backing toward the front end of the tunnel. When this occurs, coil 156 is energized through normally-closed overload contacts 158. As coil 156 is energized, it closes all three normally-open contacts 156a, 156i) and 1560 (FIG- URE 6) that energize the circuit to the reverse direction plow servo-motor 86R (FIGURE 2) so as to actuate same and extend the plows operatively associated therewith. Conversely, when rotation switch 152 closes in response to forward motion of the carriage, it energizes coil 160 through normally-closed overload contacts 162 and simultaneously closes the three normally-open con- 8 tacts 160a, 16% and 1600 to the forward plow actuating servo-motor 86F. In the meantime, of course, switch 154 has opened de-energizing coil 156 and opening contacts 156a, 15612 and 1560 thereof due to the forward movement of the carriage.

In this mode of operation, the lead pairs of plows remain extended while the following pairs thereof are retracted during the entire excursion through the tunnel regardless of the direction the carriage is moving. Thus, no selective reclaim is possible and the unit continues to move forward and back automatically until stopped. FIGURE 8, on the other hand, illustrates a simple manual override circuit for retracting whichever set of plows is operative so as to bypass portions of the pile. Connected in series across the main electrical feeder lines are a normally-closed STOP switch 164, a normally-open START switch 166, a coil 168, and the usual normallyclosed overload contacts 170. As START switch 166 is closed momentarily, coil 168 is energized to close normally-open contacts 172 thereof connected in parallel with switch 166 thus allowing the latter to be released to open position. As shown in FIGURE 6, coil 168 must also be energized to close its three normally-open contacts 168a, 1681; and 168c in the incoming feeder lines thereby energizing the servo-motor control circuits previously described. Accordingly, unless START switch 166 is closed, all of the plows are retracted and the carriage moves along the tunnel without picking up any material. Normally, of course, this switch 166 is closed except when it becomes necessary to bypass a portion of the stack. To accomplish the latter, STOP switch 164 is opened momentarily breaking the circuit to coil 168 which allows all of the contacts controlled thereby, namely, 172, 168a, 1681) and 1680, to open thus rendering the plows inoperative as they return to retracted position under the influence of their return springs. To again reactivate the plows having bypassed a portion of the pile, it is again necessary to reactivate the START circuit by closing START switch 166.

Having thus described the several useful and novel features of my traveling plow feeder, it should be apparent that the many worthwhile objectives for which it was developed have been realized. While but a single specific embodiment of the invention has been illustrated and described herein, I realize that certain changes and modifi cations will occur to those skilled in the art within the broad teaching hereof.

What is claimed is:

1. In combination in a tunnel-type bulk storage reclaim system for removing free-flowing granular materials: a tunnel adapted to support piles of the material to be reclaimed, said tunnel having elevated openings along the sidewalls thereof and horizontal shelves disposed beneath said openings in position to receive the piled material gravitating therethrough; rail means extending the length of the tunnel along the bottom thereof; endless belt conveyor means extending through the tunnel between the rail means adapted to deliver the material deposited thereon out through the open end; a wheeled carriage mounted for rolling movement along the rails straddling the belt conveyor means, said carriage including openbottomed hopper means positioned and adapted to receive material swept from the shelves and deposit same upon the conveyor means; reversible drive means operatively associated with the carriage adapted upon actuation to move same between the ends of the tunnel; forward and reverse retractable V-shaped plow means mounted on the carriage atop the hopper means for movement therewith between the shelves, both of said forward and reverse plow means being adapted in retracted position to bypass material lying atop the shelves, said forward plow means being adapted in extended position to sweep material from the shelves into the hopper means when the carriage is moving forward, and said reverse plow means being adapted in extended position to sweep material from the shelves into the hopper means when said carriage is traveling in reverse; forward plow actuating means connected to the forward plow means operative upon actuation to shift the latter between extended and retracted positons; reverse plow actuating means connected to the reverse plow means operative upon actuation to shift the latter between extended and retracted positions; and, plow actuator control means connected to the forward and reverse plow actuating means responsive to forward movement of the carriage so as to extend the forward plow means while retracting the reverse plow means, and said control means being responsive to reverse movement of the carriage so as to extend said reverse plow means and retract said forward plow means.

2. The combination as set forth in claim 1 which includes: plow actuator control override means connected to the plow actuator control means operative upon actuation to retract the extended plow means thereby bypassing a portion of the material upon the shelves.

3. The combination as set forth in claim 1 which includes: carriage reversing means connected to the reversible drive means of the carriage, said reversing means being responsive to the arrival of the carriage at opposite ends of the tunnel to reverse said drive means.

4. The combination as set forth in claim 1 in which: the forward and reverse plow means each include at least two sets of plows mounted upon the carriage in longitudinally-spaced relation to one another; and, in which the forward and reverse plow actuating means are operatively connected to all plow means of their respective sets so as to actuate same simultaneously.

5. The combination as set forth in claim 1 in which: the forward and reverse plow actuating means comprise electro-mechanical servo-motors.

6. The combination as set forth in claim 1 in which: the reversible drive means comprises a reversible electric winch disposed at one end of the tunnel, an idler pulley mounted at the other end of the tunnel, and a cable reaved from one end of the carriage, around the idler, along the bottom of the tunnel to the winch and thence to the other end of the carriage.

7. The combination as set forth in claim 1 in which: electrical lines extend through the tunnel alongside the rail means; a trolley is carried by the carriage operatively connected to the electrical lines for supplying electrical power to said carriage; the forward and reverse plow actuating means are electrically-powered servo-motors; and, the forward and reverse plow actuator control means com prise a forward rotation switch connected in series with the forward plow actuating means and a reverse rotation switch connected in series with the reverse plow actuating means, said forward rotation switch being responsive to forward movement of the carriage so as to close the circuit to the forward plow actuating means and extend the forward plow means, and said reverse rotation switch being responsive to reverse movement of the carriage so as to close and actuate the reverse plow actuating means in a manner to extend the reverse plow means.

8. The combination as set forth in claim 2 in which: the forward and reverse plow actuator means comprise electro-mechanical servo-motors operative upon energization electrically to extend their respective plow means, said servo-motors including a spring return operative to retract the plow means associated therewith upon de-energizati-on thereof; and, in which the forward and reverse plow actuator control means comprise forward and reverse switches connected to their respective forward and reverse plow actuating means, said forward switch being responsive to forward movement of the carriage so as to close and energize the forward plow actuating means, and said reverse switch being responsive to reverse movement of the carriage so as to close and energize the reverse plow actuating means.

9. The combination as set forth in claim 5 in which: the electro-mechanical servo-motors are electrically-actuated to extend their respective plows and mechanicallyactuated automatically when electrically de-energized to retract same.

10. The combination as set forth in claim 7 which includes: forward and reverse plow actuator control override means electrically connected to the forward and reverse plow actuator control means, said override means being operative upon actuation to de-energize the energized plow actuator control means thus retracting the plow means controlled thereby.

6/ 1965 Henderson. 9/1965 Booth et al.

ROBERT G. SHERIDAN, Primary Examiner.

US. Cl. X.R. 19859 

